Temperature control for internal-combustion engines



Nov. 29, 1927. 1,651,156 s, w. RUSHMORE TEMPERATURE CONTROL FOR INTERNAL COMBUSTION ENGINES Filed Aug. 11. 1924 INVENTOR ATTORNEY Jkz/zm Wfiammare Patented Nov, 29, 1927.

UNITED STATES SAMUEL W. RUSHMORE, OF PLAINFIELD, NEW JERSEY.

TEMPERATURE CONTROL FOR INTERNAL-COMBUSTION ENGINES.

Application filed August 11, 1924. Serial No. 731,322.

. My presentinvention involves the use of hot water, preferably app lled at or near boiling temperature to heat the lubricating oil in the crank cases of internal combustlon engines. The desirability of having the water near boiling for this purpose makes my device particularly useful on automobiles in which the cooling of the jacket water is by the boiling and condensing'cycle, particularly in realized in my Patent No. 1,378,724, wherein a relatively small amount of water is used and this is short circuit ed through the bottom space of the radiator, so that all the water very quickly reaches the boil ng point. While there is advantage and novelty in this combination, it will be evident that some of the advantages of my system will result where some other source of approximately boiling water is employed. Obviously, also,

the heating medium may be at temperatures substantially below boiling and may be quite widely fluctuating and still afford some measure of useful result. In general, however, it will be found that in the present day automobile and truck cooling systems where the radiator is kept full of Water and the cooling is by downflow through said radiator, the water from the jacket is too cold and may prove a refrigerating medium at the very times when heating of the lubricating oil is most needed.

Such departures from my preferred methods are undesirable, as will be more evident from consideration of the present-day difiiculties which my, invention is designed to obviate.

One of the well known serious difliculties with auto engines today is dilution of the crank case oil which results from first starting the engines when they are cold and in less degree from running engines that do not warm up sufiiciently. When the engine is too cold, the more incombustible parts of the gasoline and the products of combustion flow past even the best fitting pistons, and the steam component condenses as water in the crank case. Vith worn pistons, particularly on ill-cared for trucks, the accumulation of water in this way may run as high as 50% of the volume of lubricating oil. In all cases, the result of the dilution is to impair or destroy the lubricating quality of the oil and where accumulations of water are considerable, great trouble results in winter from freezing and bursting of pipes and combination with said cycle as.

other conduits of the oil circulating system.

It has been found that after the crank case is heatedup, there is no condensation of Water and one object of my invention is to heat the oil as rapidly as possible, thereby minimizing the condensation that can occur. Furthermore, by-using a heating medium, which is at or near the boiling point of water, to bring the oil to substantially this temperature, the additional heat supply from the motor will operate to'quickly boil off-such water as has been deposited during the warming up period. On both accounts time is a serious item, as will be evident from the fact that on some trucks it" takes as much as two hours of hard running to bring up the temperature of the crank case, and with intermittent running it may never warm above the dew point. By using boiling water as a heating medium in connection with my radiator used as an upflow steam condenser for cooling said water, my heating system is, within limits, a temperature regulator operating automatically as -a cooling system to prevent the temperature of the oil from rising above the boiling point of the water. The latter point is important since it has been found by actual test on certain trucks that the crank case temperature was as high as 240 degrees.

By thus using water maintained at the boiling point as the means for heating the oil, I obtain what amounts to constant temperature regulation within reasonable limits. My present system of heating the oil tends to be normallyself regulating for constant temperature because the functioning of the steam cooling system of my said patent keeps the water down as well asup to approximate boiling temperature. Consequently, oil temperatures in excess of the'boiling point of water, such as may be attained in hot Weather or under other special conditions. merely cause a' reverse heat exchange, the over-hot oil operating to heat the water instead of vice versa. In this way heat from the oil is liberated and disposed of through the same medium and in thesame way that heat from the cylinders is disposed'of.

My invention, however, is not limited to control of temperature of the lubricating oil by the boiling point of water and while the above functioning is always available as a limiting regulator, I prefer to employ thermostatic means controlling a valve whereby thewater regulation may be partially or wholly short circuited from the radiator outlet into the pump leading to the water jacket. Such a thermostat can be set for oil temperatures below 212 degrees in cases where this is found desirable. In such case the water at 212 will require just so much less time to heat the oil to the desired temperature and when this temperature is reached the thermostat will operate to bypass the jacket water circulation, thereby leaving in heat exchange relation with the oil only a body of relatively stationary water in position to be closed by ordinary radiation from the outside and to be heated by the oil from the inside. If the oil on the inside gets much above boiling, it will boil ofl' some of this water in the manner above described. Such thermostatic control may be highly useful even if the thermostat is set to operate at 212, since, under most conditions, oil once heated at 212 and protected by a jacket of water, even still water, will tend to heat still further by direct conduction from the engine parts and the sooner the circulation of boiling water is cutofi, the sooner will the segregated body of water begin to cool and exercise its cooling effect on the crank case.

In the latter connection, it is to be noted that while it is possible to efl'ectthe desired heating of the oil by causing it to circulate in a special pipe or conduit extending to heat exchange relation with the water in the bottom of the radiator or even in the piping, I much prefer to arrange a jacket for the bottom pan or oil collecting well in the crank case. In such case, the pan or Well portion of the crank case can be made in the form of a separate core casting, with double walls between which the water is circulated, the inner wall serving as the oil receptacle of the crank case and the outer wall as the container for the water circulation.

In the simpler forms ofthe device, the pipe leading from the bottom of the radiator will enter the water jacket at one end, while the pipe leading to the pump will be connected at the other end. Where a thermostat by-pass is desired, the entrance and exit may be closely adjacent at one end of the casting, a partial partition being interposed between the inlet and the outlet to force the circulation of the water to the far end of the jacket.

The above and other features of my invention may be more fully understood by the following description in connection wth the accompanying drawings, in which I have shown one embodiment of the principles in.

volved.

Fig. 1 is a side elevation conventionally indicating an internal combustion engine equipped with an automobile type radiator, piped for cooling by the boiling and condensing cycle, one form of heat exchanger directly from 24: through cavity for practice of my present invention being shown, in vertical section. I

Fig. 2 is a section on the line 22, Fig. 1.

Fig. 3 is a section on the line 8.3, Fig. 2.

In these drawings engine 1 is conventionally shown as having a carbureter 2, magneto 3, water circulating pump 4, fan 5, and an air cooled radiator 6. In accordance with my said patent, the hot water from the cylinder jackets flows through the pipe 7 into the bottom space in radiator '6, the water level being maintained at approximately the level of the' line as, flows from the bottom of the radiator through pipe 8 which leads to the oil heater. From the heater the pipe 9 leads to the intake of the pump 4 which discharges the water through its outlet pipe 10 into the water jacket of the engine. This outlet may be equipped with a check valve 10 for purposes described in my said patent.

The heat exchange device is shown as a single casting adapted to be bolted to the bottom of the crank case. Its inner wall 11 constitutes the receptacle into which the oil in the crank case drains. Between 'it and the outer Wall 12 is the water 'acket interspace13. The walls may be raced by castlng piers 14 betweenthem at suitable points. x

In the simpler form of my invention, all the circulation may be continuously directed through the jacket space13, but in the form shown this interspace is cast with a wall 15, 15, dividin -the inlet 16 from the outlet 17 and exten mg a substantial distance rearward so that circulation would be forced to the rear end of the jacket space.

The by-pass valve comprises a double valve head 18 adapted to-contao't either with seat-19 as in the drawings or with seat 20, orit may occupy intermediate position as determined by the actuatin thermostat 21, which islocated in the oi cavity and which operates the head through stem 22 passing'through stufling box 23. In the position shown in Fig. 2, the'hot water from the bottom of the radiators flows from pipe The water 8 through a casting affording an outlet 2% from which the water is forced through the elbow 24 into the jacket spacing 13 on the far side of the partition 15. Thence it flows out to the far edge of the partition and back on the near side tlXBIGOL WiIGHCQ it finds its way through outlet 17 into elbow v25, thence through pipe 9 to the pump. By reference to Fig. 3, it will be seen that when the valve has been forced by the thermostat into contact with seat 20, the flow will be 26, behind the valve, into the outlet 25 to the pipe 9, the flow being thus completely short cir cuited as regards the oil heating water jacket. I

The thermostat 21 is preferably of the bellows type, preferably such as is obtain- .able in the market under the name of sylphon" tube. One end of this bellows type is rigidly fixed to bracket 30 and the movable end carries a valve stem 22. I have shown this as extending through a packing box, but very little packing is necessary in the present relation, because neither the water nor the oil is under very much pressure, and the oil naturally keeps the joint lubricated and water repellant.

The oil pan and its jacket may be provided with drain plugs as at 31 and 32; also the by-pass valve may be manually operable. r

It will be evident from the above that in the present connection, use'of my patented system of cooling the jacket water by arranging the radiator as'an upflow condenser, has the advantage that the water heats quicker than in any other known system and also that in. normal operation the water is always at the boiling temperature because no matter how cold thehoneycomb of the radiator may be, it cannot have any cooling effect on the water but comes into operation only when and to the extent that steamrises from the water after the water has reached the boiling point. In other steam cooling systems the radiator operates as a down flow condenser and the condensate is always exposed to the maximum capacity of the radiator in the coldest as Well asin the hottest weather. Hence heating wiil be slow, the water in the jacket may not reach boiling point at all in cold weather and even in normal steaming operation the Water from the radiator will often be quite cold.

While I have elected to show the hot water jacket as covering only a relatively small depression or cistern into which the oil drains, this is mainly because I prefer not to unduly increase the volume and thus the time required for initial heating of the water in the cooling system, but it will be evident that the principle is the same regardless of the oil container area. and, if desired, the entire; lower portion of the crank case may be jacketed and heated as above described.

I claim:

1. An internal con'lbustion engine having a water jacket for cooling the cylinders and.

a water jacket for the oil collecting cavity in the crank case, in combination with a circulatory system for the water, including an air cooled radiator, and means for operating it as an upflow condenser to maintain boiling condensate in the bottom thereof, said means including a conduit from the upper part of the water jacket to the lower chamber of the radiator, a. conduit from the latter to the water jacket of the oil collecting space, and a conduit from the latter backto the water jacket.

2. An internal combustion engine having a water jacket for cooling the cylinders and a water jacket for the oil collecting cavity in the crank ease, in combination with a circulatory system for the water, including an air cooled radiator, a conduit from the upper part of the water jacket to the lower chamber of the radiator, a conduit from the latter to the water. jacket of the oil collecting space, and a conduit from the latter back to the water jacket, including a pump and also a by-pass and valve whereby the oil water jacketmay be short circuited from the bottom of the radiator to the pump.

3. Aninternal combustion engine having a water jacket for cooling the cylinders and a water jacket for the oil collecting cavity in the crank case, in combination with a circulatory system for the water, including an air cooled radiator, a conduit from the upper part of the water jacket to the lower chamber of the radiator, a conduit from the latter to the water acket; of the oil collecting space, and a conduit from the latter back to the water jacket, including a pump and also a bypass and valve whereby the oil water jacket may be short circuited from the bottom of the radiator to the pump, said valve being controlled bya thermostat within the crank case.

4. An internal combustion engine having a water jacket for cooling the cylinders and a.

water jacket for the oil collecting cavity in the crank case, in combination with a circulatory system for the water, including an air cooled radiator, a conduit from the upper part of the water jacket to the lower chamber of the radiator, a conduit from the latter to the water jacket of the oil collecting space, and a conduit from the latter back to the water jacket, including a pumpand also a by-pass and -valve whereby the oil water jacket may be short circuited from the bottom of the radiator to the pump, said valve being controlled by a thermostat in bathing relation to the oil in the crank case.

5. An internal combustion engine having a crank case lubrication system, a water jacket for coolingthe cylinders and a heat exchange device in operative relation for heating said crank case, in combination with exchange device in operative relation forv heating the oil-in said crank case, in comby said fluid may be circulated through the heat exchange device and returned to said circulatory system.

7. In the method of controlling the cooling and lubricating systems of internal combustion engines, the stepsjof maintaining the fluid cooling medium at approximately con-' stant boiling. temperature, and placing said fluid cooling medium in heat exchange rela-.

tion to the lubricant supply for the lubricating system.

8. In the method of controlling the cooling andlubricating systems of-internal combustion engines, the steps of maintaining the fluid cooling medium at approximately constant boiling temperature, and passing said fiuid cooling medium in heat exchange relationto thelubricant supply for the lubricating system. I

9. An internal combustion engine, having a crank case lubrication system, and a heat exchange device in operative relation to oil in said crank case, 1n combination with a circulatory system for cooling hot fluid from the water jacket, includin radiator and connections or operating it asan upflow condenser to maintain approxi-' mately constant boiling temperature for the cooling fluid, said coo ing system including also connections whereby said fluid maybe circulated through the heat exchange device and returned to said circulatory system.

Signed at F almouth Heights in the county of Barnstable, and State of Massachusetts this eighth day of August, A. 1924.

SAMUEL W, IRUSHMORE.

an air cooled 

